Method and apparatus for making dished heads



DISHED HEADS June 23, 1942.

C. B. CUSHWA ET AL METHOD AND APPARATUS FOR MAKING Filed April ll, 1940 2 Sheets-Sheet l x N E w TC R s Char/es 5. CL/f/zyva June 23, 1942. c. B. CUSHWA ETAL WETHOD AND APPARATUS FUR "AKING DISHED HEADS Filed Apr. 1 11, 1946 2 Sheets-Sheet 2 Q INVENTO RS I Char/es B. Cus/zwa and 7720mas C Kane ifwu,

Patented June 23, 1942 METHOD AND APPARATUS FOR MAKIN DISHED HEADS Charles B. Cushwa and Thomas 0. Kane, Youngstown, Ohio Application April 11, 1940, Serial No. 329,122

4 Claims. (01. 29-33) This invention relates to the manufacture of dished heads.

Dished heads are used extensively in the manufacture of tanks and haveusually been made heretofore by pressing or by spinning over a mold. Both these methods are objectionable for various reasons. Presses capable of shaping large heads cold are very expensive and the shaping of heads while hot involves the cost of furnace equipment. The method of spinning heads over molds requires that a large number of molds of various sizes and shapes be kept in stock and these molds represent a substantial investment.

We have invented a novel method and apparatus for making dished heads whereby the aforementioned objections to previous methods are entirely overcome. In a preferred practice of our invention, we provide a blank, preferably substantially circular, and reduce the thickness of an annular zone thereof spaced inwardly from the edge. This reduction is accompanied by a radial spreading of the material'of the blank. The reduction may be effected by rolling or otherwise,

and causes the edge portion of the blank to be dished laterally from its original plane. By this method, heads of various sizes and various degrees of curvature may be made easily and quickly.

For carrying out our method, we have provided apparatus including a rotatable support for the blank having blank-holding means, and a traveling roll adapted to roll down or thin an annular zone spaced inwardly from the edge of the blank We also provide means for flanging the edge of the head after it has been suitably dished.

The method of our invention will be more fully explained and the apparatus described indetail hereinafter by reference to theaccompanying drawings illustrating a preferred embodiment and practice. In the drawings,

Fig. l is a transverse sectional View through our apparatus, with parts in elevation;

Fig. 2 is a horizontal sectional View taken along the plane of line 11-11 of Fig. 1; line 1-1 of Fig.

2 illustrates the plane of the section shown in Fig. 1; and

Fig. 3 is a partial sectional view taken along the plane of line III-J11 of Fig. 1.

Referring in detail to the drawings, our apparatus comprises a base l having upstanding cdl- Transverse webs Hi and i5 posed substantially centrally of the base II].

in the base provide bearings for a supporting roll I 6. As shown in the drawings, the web I4 is dis- A motor-reducer unit I! mounted on the base I!) drives the roll it through spur gearing l8.

Transom rails l9 extend between the columns H and 12 above the base If). A clamp-supporting bracket is secured to the rails l9 substantially centrally thereof. The bracket 20 supports a vertically disposed fluid-pressure cylinder and piston 2! including a' piston rod 22. The rod 22 has a foot 23 rotatable thereon adapted tocooperate with a thrust bearing 24 on the web M to support a plate or blank, the initial position of which is indicated at 25, in position to engage the roll IS.

A carriage 26 is slidable along the rails IS. A screw shaft 21 journaled in the column I2 and bracket 20 cooperates with a nut 28 in the carriage for reciprocating the latter along the rails. A motor-reducer unit 29 mounted on a bracket 33 secured to the column [2 drives the shaft 21 through spur gearing 3 I.

The carriage 26 is provided with a vertically movable slide 32. A roller 33 is journaled in the lower end of the slide for engagement with the blank 25. As shown in Fig, 2, the axes of the roll it and the roller 33 lie substantially in the same vertical plane.

The slide 32 may be adjusted vertically by any convenient means. As an example,. We .have

shown a rack bar 34 on the slide meshing with a pinion 35 on a shaft 36 journaled in the carriage 26. the slide 32 to be raised or lowered.

The base ID has an inwardly extending web 39 and guides 40 extendfrom this web to the adjacent end of the base. A carriage 3| is slidable on the guides 40 and is provided with a slide 32. The carriage is adjusted by a screw shaft d3 journaled in the column I I and the web 39, which cooperates with a nut 44 in the carriage. The slide 42 is adjusted vertically by means of a jack screw 45 depending from a lug 46. on the slide. The jack screw 35 is threaded through a worm wheel 41 disposed within a pocket in the carriage 4|. A worm shaft 48 journaled in thecolumn H and the web 33 has -a worm 49 thereon meshing A hand-wheel 38 on the shaft 35 permits 1 carriage is provided with a vertically movable slide 55. A shaft '56 journaled in the column II and the bracket 20 has a pinion 51 splined thereon. The pinion meshes with a rack 58 on the slide 55 whereby the slide may be adjusted vertically on rotation of the shaft 56 as by a crank 59. A roll shaft 66 is journaled vertically in suitable bearings in the slide 55. The shaft has a roll body 6| thereon. A shaping head '62 is removably secured to the roll body 6|.

A motor-reducer unit 63 on the carriage 5 drives an elongated pinion 64. A gear 65 on the upper end of the shaft 66 meshes with the pinion 64 whereby the unit 63 drives the roll 6| in the various positions of the slide 55.

A screw shaft 66 journaled in the column I and the bracket 20 cooperates with a nut 67 disposed in a pocket formed in the carriage 54 and is effective to cause traversing movement of the carriage. The carriage is so constructed that pinion 51 moves with it.

Our method of making dished heads by the aid of the apparatus above described, contemplates the disposition of a blank such as that shown at 25 on the thrust bearing 24 and supporting roll I6. The slide 32 on the carriage 26, the slide 42 on the carriage 4|, and the piston rod 22 are retracted before the plate is placed on the thrust bearing and supporting roll. The plate 25 ispreferably in the form of a substantially circular blank, but means for trimming a square plate to circular form may be incorporated in the apparatus if desired. When the blank has been positioned substantially centrally on the thrust, bearing 24, fluid pressure is admitted to the cylinder 2| to advance the piston rod 22 and cause the foot 23 to clamp the blank in position. The motor-reducer unit I1 is then rolls 53 and 6| may be effected to bend the edge of the dished blank inwardly to form a flange for attachment to the shell of a tank as by welding or riveting. During the flanging operation, the motor-reducer unit 63 is operated to drive the roll 6| and this causes the blank to revolve so that the fianging is effected progressively. The roll l6 may or may not be continued in operation during the flanging.

The head 62 of the roll 6| is shaped to provide the desired radius of curvature between the flange as finally formed and the body of the dished head. After the fianging has been completed, the dished head may be trimmed circumferentially by suitable means, not shown.

It will be apparent that the extent of dishing effected is dependent upon the amount of thinning and spreading of the annular zone of the blank spaced inwardly thereof. For this reason, it is possible to shape blanks of various sizes to different degrees of curvature on the same apparatus. The manipulation of the rolls 53 and 6| which is necessary to effect the flanging operation is obvious, and requires no further description. These rolls may be adjusted horizontally and vertically by the various adjusting shafts to bring them into prop-er cooperative relation.

When the flange has been formed, the rolls 53 and 6| are retracted and the clamping foot 23 is raised so that the completed head is free for removal from the apparatus.

operated to drive the roll l6. "I'he carriage 26 is then adjusted to about the position in which it is shown and the slide 32 lowered until the roller 33 engages the blank. When sufficient pressure is exerted by the roller 33 on the blank 25, the rotation of the roller 6 will cause the blank to revolve about the axis of the piston rod 22 and thrust bearing 24. When the blank is being revolved in this manner, the application of further pressure thereto by the. roller 33 will effect a thinning of an annular zone of the surface of the blank spaced inwardly therefrom, accompanied by a radial spreading of the material of the blank. The carriage 26 is preferably adjusted inwardly as this thinning and spreading occurs, to distribute it over an annular zone of substantial width.

The effect of the thinning and speading of the annular zone spaced inwardly from the edge of the blank is to dish the edge out of the original plane of the blank, as indicated at 68. This result follows necessarily because the periphery of the blank remains unaltered and the thinnin and spreading of the annular zone spaced inwardly therefrom increases the area of the plate and has the same-relative effect as would be produced by a contraction of the periphery.

By suitably manipulating the slide 32 and the carriage 26, the desired degree of thinning and spreading may be effected to secure the desired curvature or dishing of the blank. When this has been accomplished, the slide 32 is raised. The flanging rolls 53 and 6| are then brought into action by raising the slide 42 and shifting the carriage 4| inwardly to the desired extent. By similar adjustment of the carriage 54 and the slide 55, the desired cooperation between the It will be apparent that the invention is characterized by numerous advantages over previous methods and apparatus for making dished heads. The apparatus is relatively simple and inexpensive and may be employed to produce a wide variety of shapes and sizes of heads. The cost of expensive presses and the complications incident'to hot shaping are entirely avoided, as well as the necessity for maintaining a supply of molds or forms for each different size or shape of head.

Although we have illustrated and described but a preferred embodiment and practice of the invention, it will be understood that changes in the construction and operation disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. In a method of making dished heads, the steps including providing a substantially flat plate, thinning the plate along a generally circular path spaced inwardly of the edge of the plate, spreading the material in said path radially, thereby causing the material adjacent said edge to dish out of the general plane of the original plate, and thereafter bending up the edge of the plate.

2. In a method ofmaking dished heads, the steps including providing a, substantially flat, circular plate, thinning the plate in an annular zone spaced inwardly of the edge thereof, spreading the material in said zone radially, thereby dishing said edge out of its original plane, and thereafter bending up the edge of the blank.

3. Apparatus for dishing heads comprising means securing a blank in position for rotation about a substantially central point, a supporting roll disposed radially of the blank, the periphery of the roll being in contact with the blank, a working roll adapted to engage the side of the blank opposite that which engages the supporting roll, and auxiliary working rolls movable toward and from said blank and radially there if, effective to turn up a flange around said blank.

rotation on substantially vertical axes movable toward and from said blank and radially thereof, effective to turn up a flange around said i 5 blank.

CHARLES B. CUSHWA. THOMAS C. KANE.

ing roll, and auxiliary working rolls journaled for" 

